Paolo Pavone

Parameters affecting bolus geometry in CTA: a review.

CT angiography (CTA) is based on acquisition of data during the arterial phase of contrast material passage. CTA needs timing of the contrast bolus, which should be based on accurate knowledge of bolus geometry. Experimental and human studies on bolus geometry and bolus timing in CTA were reviewed. Important parameters of bolus geometry and methods of bolus timing (test bolus and bolus tracking) are described. Recommendations are given for an optimal CTA protocol.

Lipomatous tumors of the stomach: CT findings and differential diagnosis.

This article reviews the computed tomography imaging features of a variety of gastric tumors containing fatty tissue. Lipoma, angiolipoma, liposarcoma, and teratoma are described. Differential diagnosis includes primary and reactive lipomatosis, carcinoma engulfing the perivisceral fat thus mimicking differentiated liposarcoma, and mesenchymal gastric and peritoneal neoplasms.

Bilateral ganglion cyst of the common peroneal nerve

Abstract. Ganglion cysts of the common peroneal nerve are rarely described in the literature and a bilateral lesion has not been previously reported. We present a case of a 41-year-old man with a bilateral cyst of the common peroneal nerve diagnosed with ultrasound and magnetic resonance imaging.

From maximum intensity projection to volume rendering

Three-dimensional medical images can be generated with a variety of computer algorithms from computed tomography and magnetic resonance data sets. The most commonly used techniques are maximum intensity projection (MIP) and shaded surface display (SSD). Recently, volume rendering (VR) has become available on dedicated workstations, providing the possibility of interaction with data sets. All 3D rendering techniques represent a volume of data in 1 or more 2-dimensional (2D) planes, conveying the spatial relationships inherent in the data with the use of visual depth cues. Techniques and artefacts regarding MIP, SSD, and VR are described here, along with several models of clinical application.

Focal Castleman disease of the lung MRI findings

Castleman disease is an uncommon benign disorder mainly affecting mediastinal lymph nodes and rarely visceral organs. The most typical structural finding is hypervascularity which can be well demonstrated both by CT and MRI. We report MR findings of an unusual case of solitary parenchymal lung involvement.

Primary effusion lymphomas in AIDS: CT findings in two cases

Abstract Primary effusion lymphomas represent an unusual subset of AIDS-related non-Hodgkins lymphomas. They are associated with herpes virus 8 and Epstein-Barr virus and characterized by predominant involvement of the serous body cavities (pleura, pericardi

MR Angiography of the Carotid Arteries: Parameters Affecting Image Quality

RATIONALE AND OBJECTIVES This study was performed to evaluate the relationship between dose levels of contrast medium and image quality in magnetic resonance (MR) angiography of the carotid arteries with fluoroscopically monitored, manually triggered, elliptically ordered image acquisitions. MATERIALS AND METHODS Twenty-five patients with clinical indications for angiography of the carotid arteries were examined with MR at 1.5 T by using a fluoroscopically monitored, manually triggered, elliptically ordered pulse sequence with the administration of one of three different volumes of gadolinium-based contrast medium. The signal intensities of the vessel lumen and the surrounding tissues were measured in single partitions at the origin of the common carotid artery, the carotid bifurcation, and the intracranial internal carotid arteries. The contrast-to-noise ratio in these regions of interest also was measured. Maximum intensity projection image quality was appraised for blurring, artifacts, venous enhancement, background suppression, and contrast medium distribution. RESULTS No artifacts or venous enhancement was observed. The position of the fluoroscopic section affected the distribution of contrast medium along the vessel, as evidenced by the difference between the contrast-to-noise ratio at the origin of the common carotid artery and the ratio at the carotid bifurcation and the intracranial internal carotid arteries (P < .01). The contrast medium dose administered was strongly correlated with image quality (r = 0.90). CONCLUSION Contrast medium dose is related to image quality in MR angiography of the carotid arteries performed with elliptical ordering, fluoroscopic monitoring, and manual triggering.

Improving the results of virtual colonoscopy: what the future will bring.

Several studies show the possibility of using virtual colonoscopy in radiologic routine. To understand what its future holds, a deep insight into the techniques and pitfalls is mandatory. Currently, patient preparation and insufflation methods have to be improved because they represent the main source of pitfalls. Acquisition techniques currently provide only morphologic information, which is inadequate in the case of flat lesions. Functional information is needed but not yet available. Although the development of postprocessing techniques during the past few years has been rapid, virtual colonoscopy cannot yet be proposed as a screening technique. State-of-the-art technology, however, allows us to imagine that in the near future it will become a tool suitable for routine application.

MR characterization of hepatic lesions by t-null inversion recovery sequence

Tissue characterization of focal hepatic lesions was performed employing an inversion recovery sequence with short repetition time and short inversion time (TI) values. Different and specific TI values, correlated to the in vivo measured T1 relaxation times, were used to null the signal intensity of each type of lesion. In 40 patients studied, we observed the nulling effect of normal liver in 10 of 10 cases with a TI of 136 ms, of metastases in 7 of 8 cases with a TI of 175 ms, of hemangiomas in 15 of 16 cases with a TI of 200 ms, and of cysts in 6 of 7 cases with a TI of 235 ms. A quantitative analysis of the nulled signal was performed by measuring the signal/noise values. A further qualitative and quantitative characterization was carried out by evaluating the signal intensity of hepatic lesions at the null point of normal liver. The method provided the possibility of discriminating different focal lesions with specificity values of 83-94%, according to the type of lesion.

Small cell carcinoma of the uterine corpus: CT appearance.

We report a rare case of small-cell carcinoma of the uterine corpus. To our knowledge, this is the first radiological report. Computed tomography (CT) demonstrates a hypodense lesion within the endometrial cavity with nonhomogeneous contrast enhancement.